On Sept. 17, 2026, the Washington Supreme Court overturned a voter-approved initiative on natural gas regulations, ruling it violated the state constitution's single-subject rule.
The measure — known as Initiative 2066 — was approved on Nov. 5, 2024, and concerned natural gas regulations, prohibiting legal restrictions or penalties on access to natural gas and requiring both private and public utility suppliers to provide natural gas to consumers. Additionally, the measure repealed HB 1589, passed by the state legislature in 2024, which related to large utilities reducing greenhouse gas emissions.
The state Supreme Court's 6-3 decision affirmed a previous ruling by the King County Superior Court. The opinion was written by Chief Justice Debra Stephens, who stated that the initiative included, "several provisions with markedly distinct purposes and regulatory effects, embracing four distinct subjects. It is not possible by judicial construction to sever and save any of the separate provisions and therefore I-2066 is unconstitutional in its entirety."
The state's single-subject rule provides that “No bill shall embrace more than one subject, and that shall be expressed in the title.” The rule was part of the original state constitution. Of the 26 states that allow at least one type of statewide citizen-initiated measure, 17 have a single-subject rule. Since 2010, voters in three states — Arizona, North Dakota, and South Dakota — have decided on four constitutional amendments to adopt single-subject rules for ballot initiatives. Arizona and South Dakota adopted the constitutional amendments. In North Dakota, the first measure — Constitutional Measure 2 — was rejected in 2024. However, the second measure — Constitutional Measure 1 — was approved by voters on June 9, 2026.
In response to the ruling, Caitlin Krenn, director of Washington Conservation Action's Climate and Clean Energy program, said, "Today's ruling is a huge win for Washingtonians who want to secure a healthy, affordable future. Initiative 2066 was a deceptive attempt, backed by a megamillionaire, to lock our state into expensive, polluting fossil fuels for decades and undermine the State's climate policies. By upholding the state's constitution, the Supreme Court has put us back on track to reap the benefits of cheaper, cleaner renewable energy."
Brian Heywood, founder of Let's Go Washington, an organization that supported Initiative 2066, said, "Today, Washington's initiative process is weaker than it was yesterday. [Voters] made their decision and exercised a constitutional right reserved for the people. Today, that decision was erased by a biased and one-sided court."
Voters in Colorado will decide on a similar measure to Initiative 2066 on Nov. 3, 2026. The measure—Amendment 82—would grant consumers the right to purchase natural gas for cooking or heating in homes or businesses, and allow distributors and utilities to sell natural gas to consumers.
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